I enjoyed that but I can see that it may have been a bit of a specialist fan construction.

I think I may have mentioned before that, in the wilderness years between the show's cancellation in 1989 and its revival in 2005, fan circles had a regular small industry in producing articles on the subject of how you would modernise Doctor Who if and when it returned to the screen. The prevailing wisdom was that too much harking back to old friends and enemies, while fan pleasing, tended to lose the general viewer. One of the surprises, therefore, of the later Davies seasons was the enthusiasm with which the general public embraced returning companions and battles between Daleks and Cybermen.

I hear that the general public was alienated by Let's Kill Hitler. Frankly, I have everyone I speak to on a regular basis far too well trained in Who lore to count as the general audience so I'm taking that on hearsay. But it does seem to me that Let's Kill Hitler was playing a very different game, in terms of backwards references, than a Davies style everyone meets everyone else finale.

The Daleks and the Cybermen are as much a part of the public's folk memory of Doctor Who as the Doctor and the Tardis are. Similarly people can easily recall companions from two to three years ago without necessarily needing to recall every detail of everything that happened to them in their time with the Doctor.

Let's Kill Hitler on the other hand is clearly part of the puzzle box Moffat is creating surrounding River Song and the Doctor's apparent death in The Impossible Astronaut and it relied, critically, on remembering details of who said what to whom at what point in interleaved time lines. In short, it required people to be on top of the detail in order to feel included in the plot.

I loved it but then I'm quite a puzzle boxy detail sort of person. I thought the joke about temporal grace was funny, and I had to explain that to B. so I assume it completely passed most people by. But I also enjoyed the sense of fun the episode seemed to have and the way Rory just gets better and better. I laughed at the miniturisation ray joke as well.

I fear that this story was a bit too much of a fan pleaser or perhaps, given the way it is slotted into the middle of season arc, a fan teaser. You can see that this episode is attempting to be a bit of a fun run-around, presumably in the hopes that non-fans won't worry too much about all the River Song baggage and will simply enjoy the ride. But I suspect that River Song was far too much in the foreground to be overlooked.

I'm not a super huge hardcore fan of Doctor Who (haven't seen any of the old stuff), but I was able to follow quite easily.I prefer stories that keep the viewer thinking and wondering over those that just repeat everything until the dumbest one understands.

I too prefer to have some thinking required, and Moffat has a good reputation in terms of piecing complex stories together, even if he does tend towards puzzle stories rather than ones that focus more on the complexities of character. I hope there are more people out there who like this sort of thing! The popularity of crime fiction and closed-room mysteries would suggest there is an appetite for it but, of course, people may not expect that kind of story-telling from something with action-adventure trappings.

Yes. But like you said, the episode sure was enjoyable for those who didn't want to think too much about it too. And there are enough monster-of-the-week episodes to keep everyone entertained. I think it's keeping a very good balance there, even if there are other aspects of the series I don't like as much.